Wedging pawl type wrench



Feb. 20, 1951 R. E. GEARHART 2,542,323

WEDGING PAwL TYPE WRENCH Filed oct. .3, 1949 7l v E 75 jp 7i ,73

Patented Feb. 20, 1951 `UNITED STATES PATENT OFFICE WEDGING PAWL TYPE WRENCH Roy E. Gearhart, Kansas City, Mo., assigner of one-half to Charles E. Hose, Kansas City, Mo.

Application October 3, 1949, Serial No. 119,346

Claims. l

This invention relates to new and useful improvements in wrenches, and has particular reierence to wrenches of the "c1utch or ratchet types, wherein nuts, bolts, or the like may be driven in one direction while the tool handle is moved reciprocally, without disengaging thev tool from the work.

The principal object of the present invention is the provision of a wrench comprising a driving member, a driven member, a pawl carried movably by said driving member and adapted to engage said driven member operatively when said driving member is moved in one direction, and means for retracting said pawl out of engagement with said driven member when said driving member is moved in the opposite direction.

Another object is the provision of a wrench including a driving member, a driven member, a pawl disposed in floating relation between said driving and driven members and adapted to engage said driven member operatively, said pawl being driven by said driving member but having a period of lost motion relative thereto, and cam means carried by said driving member and operable during said period of lost motion to move said pawl into operative engagement with said driven member when said driving member is turned in one direction, and to move said pawl out of engagement with said driven member when said driving member is turned in the opposite direction.

A further object is the provision of a wrench which is noseless in operation and` has negligible drag or resistance to turning on ,its return strokes.

A still further object is the provision of a wrench of the c`ass described having cam means for controlling the position of the pawl relative to the driven member, of means for `adjusting said cam means whereby the wrench may be adapted to turn the work in either direction.

Other objects are the. provision of a pawl having a large number oi teeth in engagement with the driven member, whereby great strength is provided, the provision of a wrench having a minimum number of parts, economy and simplicity of construction, eiiiciency and dependability of operation, durability, and adaptability for use in various types of tools wherein an oscillating or ratchet drive is desired.

With these objects in view, as well as other objects which will appear in the course of the specication, reference will be had to the drawing, wherein:

Figure 1 is a side elevation of a. wrench embodying the present. invention, with parts broken away.

Figure 2 is a plan view of the head portion of the wrench shown in Fig. 1.

Figure 3 is an inverted plan view of the head portion of the wrench shown in Fig. 1.

Figure 4 is an enlarged fragmentary section taken on line 'IV-IV of Fig. 2.

Figure 5 is a section taken on iine V-V of Fig. Ll, showing the parts in the neutral position.

Fig. G is a View similar to Fig. 5, showing the parts positioned for a lett-hand drive.

Fig. 'T is a view similar to Fig. 5, showing the parts positioned for a right-hand drive.

Fig. 3 is a view similar to Fig. 5, showing the parts positioned for a right-hand drive, but during the return or rearward stroke of the handle.

Fig. 9 is a side elevation of a modiiication of the device adapted for use as a socket adapter for use with interchangeable extension handles, a representative extension handle being shown in dotted lines.

Fig. l0 is an enlarged section taken on line X- ofFig. 9,

`Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to a hollow, cylindrical body member closed at one end by wall i and having an integral handle E extending radially therefrom. A square driving lug 8 is integral and coaxial with body member 2 and extends inwardly from the inner surface of wall Ll. The planar Surfaces of said lug parallel to the axis oi the body member are for convenience designated as side walls l0 and I2 and end walls I4 and I5. Said lug has an axial cylindrical bore i3 formed therethrough. An annular setting plate 20 is disposed against the outer surface of wall fi, being carried for rotational oscillation on a cylindrical boss 22 extending outwardly from wall 4 coaxially with the body member. Said setting plate is held on said boss, and frictionally positioned relative to the body member by a snap ring 24 which engages a peripheral groove 25 formed in boss 22 Said setting plate may be turned by means of a knurled handle 28 integral therewith. A pin 35i is iiXed in said setting plate and extends inwardly into body member 2 thorough an arcuate slot 62 formed in wall 4. Said pin is parallel with the axis of the body member and said slot is disposed concentrically to said axis. Said slot is disposed adjacent end Wall I6 of driving lug 8, and is substantially coexten'sive therewith.

An annular pawl ring 34 ts rotatably within body member 4, and the inner surface of said ring is formed to present teeth 36 around the entire periphery thereof, Said teeth extending parallel to the axis of the body member. The pawl ring I ent shapes.

wall 38. An axial stem d!! extends inwardly from wall 38 and is carried for rotation in bore I8 of lug 8. A headed screw 112 extends through boss 22 and wall 4 and is threaded into stem Mi, thereby holding the body member and pawl ring in assembly. `The head of said screw is countersunk in boss 22.

Wall 38 is formed to present an outwardly extending axial stem Mi, preferably square in crosssection, adapted to fit into a correspondingly shaped hole t6 formed in an ordinary wrench socket member d8. Said socket member is retained on said stem by a detent ball 50 embedded in a recess 52 formed in stem 4d and urged outwardly by a spring 54 carried in said recess. Said ball is adapted to engage a recess 55 formed in the wall of hole 5. Socket member 4B has a noncircular recess 53 formed in its outer end for engaging nuts, bolt heads, and the like. Said vsocket members are usually sold in sets, having work engaging recesses of graduated sizes and differ- This type of socket, as well as its mounting, is common and no claimis made specifically thereto. course, be extended outwardly from the body member, and the work engaging recess 58 formed directly therein, without departing from the spirit of the invention.

A nat, roughly circular pawl 62 is carried within pawl ring 3d, tting slidably between body member wall 4 and pawl ring wall 38, asbest shown in Fig. 4. A roughly rectangular hole 62 is formed 'centrally through said pawl, into which square driving lug 8 and pin 30 extend. Referring principally to Figs. 5 to 8, it will be noted that the side walls of hole E2, or those walls adjacent side walls I@ and l2 of lug S, are each formed of two planar sections converging inwardly to an obtuse angle substantially at the transverse axis of the hole. Thus relatively angled walls 54 and 56 are formed adjacent lug wall I0 and walls 68 and l0 are formed adjacent lug wall i2, wall 6E being parallel to wall 10 and wall 66 being parallel to wall 68. The end wall of hole 62 adjacent end wall lll of lug 8 is provided with a central section 'I2 parallel to the transverse axis of the hole and end sections i4 and '1S inclined relatively outwardly, wall 'Iii being at right angles to wall 6G and wall 76 being at right angles to 7 wall 10.

The portion of the outer periphery o pawl 5E! ring 3S. The pawl is adapted to move Within pawl ring 34 longitudinally to hole 52 either into ment with said pawl ring, wall 'l2 of hole 62 rests against wall ill of lug The wall of hole B2 opposite wall lZ--'5, and adjacent lug wall I5, is formed to present an Yarcuate central section 80 having a radius of curvature equal to the radius of movement of the outer edge of pin r3l), and outwardly inclined cam sections 82 and 84 at the ends of said arcuate section. Cam wall 84 is slightly divergent inwardly from wall 15, and cam Wall 82 is likewise divergent from wall 14, in order that lug 8 and pin 30 may turn as a unit within hole 62 of the pawl without binding. A leaf spring 86 is xeol at one end in pawl 60, and bears resiliently against the toothed inner surface of pawl ring 34 diamet- The pawl ring 3d could, cf

. cam wall 84 of the pawl.

' corresponding to' and substantially ooextensive with wall 'l2-'li-'I6 of hole 62 is formed to present teeth 78 adapted to engage teeth 36 of pawl rically opposite the toothed portion of said pawl. This spring urges the pawl toward engagement with the pawl ring, and provides a brake resisting the rotation of the pawl in the pawl ring. Pawl 60 is provided at its outer periphery with rounded projections S8 substantially on the transverse axisof hole 62. These projections serve -to prevent undue transverse movement of the pawl relative to lug 8.

The operation of the wrench`is substantially as follows: Referring to Fig. 5, which shows the parts in the neutral position, it will be noted that pin 30 has been moved to the central part of slot 32 by means of handle 28. In this position pin 3G engages arcuate wall 30 of pawl hole 62 to retract pawl 6G out of engagement with pawl ring 34. It will be noted that wall coincides with the path of the outer edge oi pin 30, and that wall 'Z2 of pawl hole 552 is held against wall E4 of lug 8. The pawl is thus held out of engagement with the pawl ring, and is locked against rotation on lug 8, and handle 5 may be rotated freely in either direction without causing the pawl to engage the pawl ring.

To provide a left-hand drive, handle 28 is turned to move pin 3@ to the lower end of slot 32, as shown in Fig. 6, said pin then resting substantially at the junction of arcuate wall 8i! and Handle is then turned in the direction indicated by the arrow in Fig. 6, thereby causing lug 8 Vto turn in pawl hole 62. As this turning occurs, lug wall ld, contacting the pawl'at the juncture of walls E2 and l5 of said pawl, cams the pawl transversely to the axis oi' the wrench to move the teeth 'i3 thereof into engagement with teeth 3G of the pawl ring. During this transverse movement of the pawl, pin 39 rides along cam wall Sd of the pawl, the outward inclination of said wall permitting transverse movement of the pawl. The parts are so proportioned that at the same time that the pawl and pawl ring reach full engagement, wall 'I4 of lug 3 comes into planar Contact with wall of the pawl hole, and the side walls it and i2 of the lug respectively contact walls 8l! and iE of the pawl hole. Spring 86 also assists in moving the pawl into engagement with the pawl ring. .The parts then have the relation shown in Fig. 6, and the wrench is adapted for a left-hand drive. The torque applied to driving lug 3 by handle 5 is appliedto pawl 60 by the engagement of walls 64 and l0 of said pawl against walls Il) and I2 of said lug, is transferred to pawl ring 3d by said pawl, and thence to wrench socket d3. The engagement of lug wall I4 with wall 'I5 of the pawl holds the pawl firmly in engagement with the pawl ring, and also imparts rotational torque to the pawl.

Fig. 7 shows the parts correspondingly positioned for a right-hand drive. Pin 30 has been moved to the upper end of Slot 32, and handle 6 turned in the direction indicated by the arrow. Lug walls i0 and l2 bear respectively against walls 56 and 58 of the pawl, and lug wall i4 bears against wall 'le of the pawl. It will bek noted that in neither the right or left-hand drives does pin 5G support any of the load.

Fig. 8 shows the parts positioned for a righthand drive, but during the rearward or ratcheting stroke of handle ii. If, with the parts in the driving position'as shown in Fig. 7, handle 6 is turned ina reverse direction as indicated by the arrow in Fig. 8, lug 8 and pin 30 will turn as a unit about the axis of the wrench, and pin 36, acting on cam wall 82 ofthe pawl.

will cam the pawl out of engagement with pawl ring'34. When the pin reaches the juncture between cam wall 82 and arcuate wall 80, as in Fig. 8, the pawl is fully retracted, wall 12 the-reof resting against lug wall ifi. The pawl is thereb'y secured against further rotation relative to the lug and handle e may be turned freely. When the direction of rotation. of handle 5 is again reversed, the pawl will be cammed into engagemerit with pawl ring 3Q by lug 8 as previously described.

From a consideration of Figs. 6 and 7, it is apparent that when pin 33 is disposed at either end o 'f slot 312, and pawl 6E! is in engagement with the pavvl ring, pin ell cannot be moved in slot 3E, diie to the fact that one or theother of cam walls 32 and Sii of the pawl extend across the path of said pin. For this reason, in order to adjust pin 3!! in slot 32 by means of handle 28, it is iirst necessary to back handle t slightly to move pawl Bil to its retracted position, as shown in Fig. 8. Pin 3d may then be freely adjusted with handle 28. This feature prevents accidental movement 'of the pin when a load is being applied by the wrench, which would of course retract the pawl.

Since pavvl @il is positively cammed both into and out of engagement with the pavvl ring, it is apparent that the wrench would function properly in most circumstances even if spring 85 were omitted, the pawl having suincient inertia to resist rotation as it is cammed laterally by lug 8 and spring 30. However, the spring is elective to provide a slight braking action on the rotational movement of the pai-.vl relative to the pawl ring, thereby neming the pawi against rotation as it is c'a'rnm'ed laterally. This provides a more positive pawl action, preventing skipping of teeth as `the pavvl moves into engagement, and reduces the outwardly extending axial boss t2, corresponding toboss Z2 of the vpreferred form, said boss having a squared recess 'gli in its Vouter end for receiving the correspondingly shaped end of any of various types oi extension handles for driving the Wrench. `A representative type o1" handle 95 is shown in dotted lines in Fig. 9. The setting plate 38,'whic`h `corresponds to 'setting plate 2d of the preferred `form, is of slightly longer diameter than body member 2 and has its edge knurled for easy turning. An indicator finger .ille is carried by said `r'ilate and cooperates vwith indicia 92 imprinted von body member 2 to indicate the setting of pin 30. The construction and operation ofthe modied'wrench is otherwise identical with that of the preferred form.

Thus it is apparent that a Wrench having several advantages has been produced. It is eX- tremely simple and economical, having only three moving parts carried by the body member. It has a minimum of lost motion, and is noiseless in operation. lt is efficient and dependable in operation, 'and not likely to get out of order. The

bodily transitional movement of the .pawl, in dis- Itinction 'to the usual pivotal mounting of ratchet baw'ls, permits the use of a "pawl having a large 6 'number of teeth, thereby providing an exceptionally strong tool. Breakage or damage of a portion of the pawl teeth will not appreciably impair the eiciency 4of the wrench.

While I have shown specific embodiments of my invention, it is apparent that many minor variations of construction and operation could be made without departing from the spirit of the invention.

What vclaim as new and desire to protect by Letters Patent is:

l. A wrench comprising a manually rotatable body member, a pawlring carried for coaxial rotation by said body member, a work. engaging 'member carried by said pawl ring, a pawl carried by said body member for movement to and from engagement with said pavvl ring transversely to the axis thereof, said body member having a limited degree of rotational lost motion relative to said pawl, and cam means carriedby said body member and operable during said Ylost motion to move saidpavvl into engagement with said pawl ring when said body member is turned in one direction, and to move said pawl out of engagement with said pawl ring when said body member is turned in the opposite direction, said -oam means being adjustable relative to said body member whereby rotation of said body member will cause said pawl ring to be driven selectively in either direction.

2. A wrench comprising a manually rotatable body member, a pawl ring carried for coaxial rotation by said body member, a work engaging member carried bysaid pawl ring, a pav/l car ried by said body member for movement to and from engagement with said pavvl ring transversely to the axis thereof, said body member having a limited degree of rotational lost motionrelative to said pawl, cam means carried by saidbody member and operable during said lost motion to move said pawl into engagement with said pawl ring when said body member is turned in one direction, and to move said pavvl out of engagement with said pawl ring when said body member is turned in the opposite direction, frictional means resisting rotation of said pavvl relative to `said pawl ring, and means for adjusting said cam means whereby said pavvl may be caused to drive said pavvl ring in either direction or retracted to a neutral position out or" engagement with said pawl ring.

3. A Wrench comprising a body memben, manual means for rotating said body member, a noncircular driving lug carried rigidly by said body member in its axis oi rotation, an internally toothed pavvl ring carried rotatively by said body member concentrically about said driving lug, a work engaging member carried by Said pavvl ring, a planar pawl having a hole formed therein litting over said lug and having a portion of its periphery toothed for engagement with said pawl ring, said hole being proportioned to permit limited rotational movement oi said lug therein and movement of said pawl transversely to the axis of rotation to and from engagement with said pawl ring, said lug being adapted when turned in one direction Within said pawl to contact a wall of said hole to move said pavvl into engagement with `said pavvl ring, and a cam member carried by said body member and operable as said lug is turned inthe opposite direction Within said pawl to contact a wall of said hole to move said pawl out of engagement with said ring.

4. A wrench comprising a body member, manual means for rotating said body member. a

non-circular driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried rotatively by said body member concentrically about said driving lug, a work engaging member carried by said pawl ring, a planar pawl having a hole formed therein tting over said lug and having a portion of its periphery toothed for engagement withsaid pawl ring, said hole being proportioned to permit limited rotational movement of said lug therein and movement of said pawl transversely to the axis of rotation to and from engagement with said pawl ring, said lug being adapted as it is turned to either limit of its rotation relative to said pawl to Contact a wall of said hole to move said pawl into engagement with said pawl ring, whereby said pawl ring is driven, and a cam member carried by said body member and operable when said lug is backed away irom one of said driving positions to move said pawl out of engagement with said pawl ring.

5. A wrench comprising a body member, manual means for rotating said body member, a non-circular driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried rotatively by said body member concentrcally about said driving lug, a work engaging member carried by said pawl ring, a planar pawl having a hole formed therein fitting over said lug and having a portion of its periphery toothed for engagement with said pawl ring, said hole being proportioned to permit limited rotational movement of said lug therein and movement of said pawl transversely to the axis of rotation to and from engagement with said pawl ring, said lug being adapted as it is turned to either limit or its rotation relative to said pawl to Contact a wall of said hole to move said pawl into engagement with Said pawl ring, whereby said pawl ring is driven, a cam member carried by said body member and operable when said lug is backed away from one of said driving positions to move said pawl out of engagement with said pawl ring, and means for adjusting said cam member whereby the retraction or" the pawl may be caused to drive said pawl ring selectively in either direction.

6. A wrench comprising a body member, manual means for rotating said body member, a non-circular driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried rotatively by said body member concentrically about said driving lug, a work enga-ging member carried by said pawl ring, a planar pawl having a hole formed therein fitting over said lug and having a portion of its periphery toothed for engagement with said pawl ring, said hole being proportioned to permit limited rotational movement of said lug therein and movement of said pawl transversely to the axis of rotation to and from engagement with said pawl ring, said lug being adapted as it is turned to either limit of its rotation relative to said pawl to Contact a Wall of said hole to move said pawl into engagement with said pawl ring, whereby said pawl ring is driven, a cam member carried by said body member and operable when said lug is backed away from one of said driving positions to move said pawl out of engagement with said pawl ring, means for adjusting said cam member whereby the retraction oi' the pawl may be caused to drive said pawl ring selectively in either direction, and braking means resisting rotation of said pawl in said pawl ring,

7. A wrench Comprising a body member, a handle for rotating said body member, a square driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried for coaxial rotation by said body member vabout said lug, a work engaging mem- ,ber carried rigidly by said pawl ring, a planar pawl carried within said pawl ring and having a portion of the outer edge thereof toothed for engagement with said pawl ring, said pawl having a roughly rectangular hole formed there-I through and fitting over said driving lug, the major axis of saidihole intersecting the toothed portion of said pawl to permit movement of said pawl transversely to the axis of the body member to and from engagement with said pawl ring, a spring urging said pawl into engagement with said pawl ring, the side walls of said hole being formed to permit limited rotation of said lug therein, said lug being adapted when turned to either limit of its rotation in said hole to contact the end wall of said hole adjacent the toothed portion of the pawl, and a cam pin carried by said body member and projecting into said holek parallel with the axis of the body member, said pin contacting the opposite end wall of said hole, said last named wall being formed to present cam surfaces which are engaged by said pin when the driving lug is backed away from one ofy said driving positions to move said pawl out of engagement with said pawl ring.

8. A wrench comprising a body ymember, a handle for rotating said body member, a square driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried for coaxial rotation by said body member about said lug, a work engaging member carried rigidly by said pawl ring, a planar pawl carried'within said pawl ring and having a portion of the outer edge thereof toothed for engagement with said pawl ring, said pawl having a roughly rectangular hole formed therethrough and tting over said driving lug, the major axis of said hole intersecting the toothed portion of said pawl to permit movement of said pawl transversely to the axis of the body member to and from engagement with said pawl ring, a spring urging said pawl into engagement with said pawl ring, Vthe side walls of said hole being formed to permit limited rotation of said lug therein, said lug being adapted when turned to either limit of its rotation in said hole to contact the end wall of said hole adjacent the toothed portion of the pawl, and a cam pin carried by said body member and projecting into said hole parallel with the axis of the body member, said pin contacting the opposite end wall of said hole, said last named Wall being formed to present an arcuate central section which is concentric with the body member when the pawl is in its retracted position, and an outwardly inclined planar cam section at each end of said arcuate section, said pin resting on one of said cam sections when said lug is in driving position, whereby when said lug is backed away from its driving position said pin will cam said pawl out of engagement with said pawl ring.

9. A wrench comprising a body member, a handle for rotating said body member, a square driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried for coaxial rotation by said body member about said lug, a work engaging member carried rigidly by said pawl ring, a planar pawl carried within said pawl. ring and having a por 9 tion oi the outer edge thereof toothed for engagement with said pawl ring, said pawl having a roughly rectangular hole formed therethrough and fitting over said driving lug, the major axis of said hole intersecting the toothed portion of said pawl to permit movement of said pawl transversely to the axis of the body member to and from engagement with said pawl ring, the side walls of said hole being formed to permit limited rotation of said lug therein, said rotation being symmetrical with respect to the longitudinal axis of said hole, the end wall of said hole adjacent the toothed portion of said pawl having a central planar section parallel with the minor axis of the hole and adapted to lie flat against the corresponding wall of said lug when said pawl is in its retracted position and outwardly inclined planar end sections which respectively lie against said lug wall when the lug is turned to the limits of its rotation in said pawl, the opposite end wall of said hole having a central arcuate section which is concentric with the body member when the pawl is in its retracted position and outwardly inclined planar end sections, a cam pin carried by said body member and projecting into said pawl hole parallel to the axis of said body member to ride on said last named end wall of said pawl hole, and means for adjusting said pin concentrically about the axis of said body member between xed limits, said limits corresponding to the ends of the arcuate wall section of said pawl hole when said pawl is in its retracted position.

10. A wrench comprising a body member, a handle for rotating said body member, a square driving lug carried rigidly by said body member in its axis of rotation, an internally toothed pawl ring carried for coaxial rotation by said body member about said lug, a Work engaging member carried rigidly by said pawl ring, a planar pawl carried within said pawl ring and having a portion of the outer edge thereof toothed for engagement with said ypawl ring, said pawl having a roughly rectangular hole formed there- 19 through and fitting over said driving lug, the major axis of said hole intersecting the toothed portion of said pawl to permit movement of said pawl transversely to the axis of the body member to and from engagement with said pawl ring, the side walls of said hole being formed to permit limited rotation of said lug therein, said rotation being symmetrical with respect to the longitudinal axis of said hole, the end wall of said hole adjacent the toothed portion of said pawl having a central planar section parallel with the minor axis of the hole and adapted to lie fiat against the corresponding wall of said lug when said pawl is in its retracted position and outwardly inclined planar end sections which respectively lie against said lug wall when the lug is turned to the limits of its rotation in said pawl, the opposite end wall of said hole having a central arcuate section which is concentric with the body member when the pawl is in its retracted position and outwardly inclined planar end sections, a cam pin carried by said body member and projecting into said pawl hole parallel to the axis of said body member to ride on said last named end wall of said pawl hole, means for adjusting said pin concentrically about the axis of said body member between iixed limits, said limits corresponding to the ends of the arcuate wall section oi said pawl hole when said pawl is in its retracted position, and a frictional braking means resisting the rotation of said pawl relative to said pawl ring.

ROY E. GEARl-IART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 716,041. Houghtaling Dec. 16, 1902 1,199,737 Ayer Sept. 26, 1916 

